Cytoplasmic vacuolization usually occurs in cells treated with different agents and substances. We found that LZ-106, an analog of enoxacin, is a potent lysosomotropic agent, contributing to the formation of cytoplasmic vacuoles in cells. Studies of LZ-106-induced vacuolization in H460 cells showed acid environment inside these vacuoles. Further study demonstrated that markers in the late endosomes and lysosomes, like LAMP1 and RAB7, on the surface of the vacuoles, implying that these vacuoles might derive from endosomes and/or lysosomes. By studying the fluorescence intensity of LZ-106, we discovered that LZ-106 tended to locate in acid organelles, and Bafilomycin A1, a V-ATPase inhibitor, was able to suppress its acid organelles localization. Also, we noticed that LZ-106 could induce lysosome stress, involving pH increment and lysosomal membrane damage. Moreover, the expression levels of some lysosome-related proteins, like LAMP1, EEA1, and Cathepsin B, were also altered upon LZ-106 treatment. At last, we confirmed LZ-106 can activate TFEB, a key regulator of lysosomes. Knockdown of TFEB could also reverse LZ-106’s effect on vacuolization in H460 cells. Taken together, due to LZ-106’s lysosomotropic properties, it is able to accumulate in the acid organelles and induce lysosomal dysfunction in H460 cells, leading to TFEB activation and the following cytoplasmic vacuolization.

细胞质空泡化通常发生在用不同药剂和物质处理过的细胞中。我们发现，LZ-106（依诺沙星的类似物）是有效的溶同溶剂，有助于细胞中细胞质液泡的形成。对LZ-106诱导的H460细胞空泡的研究表明，这些空泡内部存在酸性环境。进一步的研究表明，在液泡表面上的晚期内体和溶酶体中的标记物，如LAMP1和RAB7，暗示这些液泡可能源自内体和/或溶酶体。通过研究LZ-106的荧光强度，我们发现LZ-106倾向于位于酸性细胞器中，V-ATPase抑制剂Bafilomycin A1能够抑制其酸性细胞器的定位。此外，我们注意到LZ-106可以诱导溶酶体应激，涉及pH值增加和溶酶体膜损伤。此外，LZ-106处理后，一些溶酶体相关蛋白（如LAMP1，EEA1和组织蛋白酶B）的表达水平也发生了变化。最后，我们确认LZ-106可以激活TFEB（溶酶体的关键调节剂）。抑制TFEB还可以逆转LZ-106对H460细胞空泡化的作用。综上所述，由于LZ-106的溶同性特性，它能够在酸性细胞器中积累并诱导H460细胞中的溶酶体功能障碍，从而导致TFEB活化和随后的细胞质空泡化。抑制TFEB还可以逆转LZ-106对H460细胞空泡化的作用。综上所述，由于LZ-106的溶同性特性，它能够在酸性细胞器中积累并诱导H460细胞中的溶酶体功能障碍，从而导致TFEB活化和随后的细胞质空泡化。抑制TFEB还可以逆转LZ-106对H460细胞空泡化的作用。综上所述，由于LZ-106的溶同性特性，它能够在酸性细胞器中积累并诱导H460细胞中的溶酶体功能障碍，从而导致TFEB活化和随后的细胞质空泡化。